Energy-aware power allocation for asymmetric analog network coding with statistical CSI

Energy efficiency (EE) is among the main considerations in the design of modern wireless networks. In this paper, we investigate the EE enhancement for asymmetric analog network coding (ANC) protocol of a two-way relay system based on statistical channel information. A power allocation problem is formulated as the system EE maximization problem with objective function quantified by Goodbit-per-Energy (GPE). Importantly, the EE optimization problem may not be convex and can be categorized into a nonlinear fractional programming problem. Therefore, to solve the problem, a nonlinear fractional programming based algorithm is proposed and closed-form solution is obtained, providing valuable insights into practical system designs. Simulation results highlight the effect of the proposed power allocation.